So is this in an error in the Guide? It’s confusing for a beginner needing to know accurate facts before embarking on an expensive hobby?
From ChatGPT…
No. Lit candles do not have anything to do with cyanobacteria.
There is no known biological or chemical connection between a burning candle and cyanobacteria.
A lit candle:
- Burns wax (such as paraffin, soy, or beeswax).
- Produces heat, light, carbon dioxide, water vapor, and small amounts of combustion by-products (such as soot if the flame is smoky).
Cyanobacteria:
- Are living photosynthetic bacteria.
- Need water or moisture to survive and grow.
- Are found in environments such as lakes, ponds, rivers, oceans, damp soil, and wet surfaces.
- Do not originate from combustion or burning.
If you came across a claim linking candles and cyanobacteria, it is likely based on a misunderstanding or confusion with another topic. If you can tell me where you heard or read it, I can help explain what it may have been referring to.
I had to ask a million questions and clarify what I meant to chat GPT but this is what it gave me as a response
Can candles contaminate a reef tank? Yes. Scented candles, air fresheners, aerosol sprays, incense, and essential oil diffusers all release volatile organic compounds (VOCs), fragrances, and in some cases soot particles into the air. Protein skimmers are incredibly efficient air scrubbers—they pull thousands of liters of room air through the aquarium every day. That means airborne chemicals can absolutely end up dissolved in aquarium water.
This has been documented with:
Perfumes and colognes causing skimmer overflows.
Aerosol cleaners poisoning reef tanks.
Cooking fumes affecting sensitive corals.
Smoke from cigarettes or fires introducing contaminants.
But can they increase dissolved organic carbon (DOC)?
Probably not to a biologically significant extent.
DOC in reef tanks is normally measured in milligrams per liter. The amount of carbon-containing compounds from an occasional candle that actually dissolves into hundreds of liters of water is tiny compared with the DOC produced by:
fish waste,
coral mucus,
uneaten food,
bacterial exudates,
decaying algae.
A candle might introduce trace organic compounds, but it's unlikely to raise DOC enough to drive a cyanobacteria bloom by itself.
Could they still trigger cyanobacteria indirectly? Possibly.
Some possibilities include:
Certain fragrance compounds could selectively inhibit beneficial microbes while cyanobacteria tolerate them.
Airborne soot or metals from poor-quality candles could stress corals or beneficial bacteria.
If the tank is already on the edge of instability, another stressor could allow cyano to gain the upper hand.
In that case, the candle wouldn't be "feeding" cyano so much as changing the microbial balance.
What do I think?
I think the article probably confused correlation with causation.
If someone lights candles every evening in a closed room and their skimmer is pulling that air continuously, it's plausible that airborne contaminants enter the aquarium. However, claiming that candles increase DOC enough to fuel cyanobacteria isn't well supported by the evidence we have.
In my opinion, if two otherwise identical reef tanks were run side by side—one exposed to scented candles and one not—I would expect:
perhaps a slight increase in contaminants in the exposed tank,
maybe more coral irritation if exposure was heavy,
but not a major increase in DOC or cyanobacteria solely because of the candles.
For most reef keepers, nutrients (particularly phosphate availability), excess organics from feeding, low flow, detritus accumulation, and shifts in microbial communities remain much more likely causes of cyano than a scented candle.
Actually a pretty good answer from the AI for once.
